interface PersonType2<T>{
    name:string
    age:T
}

let p11:PersonType2<string>={
    name:'Giles',
    age:'40'
}

class GirlType2<T>{
    name:string=""
    age:T|undefined
}

let g11:GirlType2<number>={
    name:"李晓红",
    age:23
}